All About Diabetic Macular Edema
Diabetic macular edema (DME) is extremely common in older people with diabetic retinopathy, but it can also occur in people who have diabetes with no other visible retinopathy. These two eye conditions are the leading causes of blindness in developed countries across the globe.
DME is often present in the later stages of retinopathy. However, research has found that it may start developing much sooner, yet it goes undetected in earlier stages.
What is diabetic macular edema?
The macula is in the center of your retina, which is located in the back of your eye and is responsible for your ability to see fine details. The macula helps you to see straight-ahead and keeps your vision sharply in focus.
Without a healthy macula, you would struggle to read text, focus on the features of a person’s face, or see critical details on the road while driving your car.
The word “edema” refers to the build-up or accumulation of fluid. The macula swells and thickens with the build-up of fluid that eventually affects your vision. The more it thickens, the more it is likely to interfere with your vision, potentially leading to irreversible blindness.
Using the International Clinical Diabetic Macular Edema Disease Severity Scale, there are mild, moderate and severe categories of DME.
- Mild: Some thickening of the retina or presence of hardened leakage not near the center of the macular
- Moderate: Thickened retina with presence of hardened leakage nearer to the center of the macular
- Severe: Thickened retina with presence of hardened leakage at the center of the macular
What causes DME?
DME can be a direct result of diabetic retinopathy, which is largely related to chronically elevated blood glucose (blood sugar) levels that damage nerves and blood vessels in the retina.
When blood vessels in the retina swell, leak and bleed, it may lead to fluid build-up in the macula.
The National Eye Institute reports that out of the estimated 7.7 million Americans with diabetic retinopathy, approximately 750,000 also develop DME.
Signs & symptoms of DME
The greatest challenge of catching DME is that it usually offers no symptoms in its earlier stages, which means it may not be detected and diagnosed until after irreversible damage has already been done.
Annual eye exams with your optometrist (eye doctor) are the only way to catch DME early enough to help prevent it from progressing and affecting your vision
Treatment for diabetic macular edema
The treatment plan for DME will depend on the severity of the condition, but there are two things everyone with DME can work on along with their health care team immediately after their diagnosis:
- Bring your blood glucose (blood sugar) levels and A1C into a safer range
- Lower your blood pressure levels to recommended goals
Then, you’ll discuss the following treatment options with your eyecare team.
Anti-VEGF injections work by blocking a protein called vascular endothelial growth factor (VEGF).
They are usually the first treatment method for DME. VEGF is overactive in DME and it’s what stimulates the growth of abnormal blood vessels which are prone to rupturing and leaking blood and fluid into the macula and the retina, worsening both DME and retinopathy.
With DME, there is leakage of fluid without the development of abnormal vessels, which is different than proliferative diabetic retinopathy.
Anti-VEGF injections also help by decreasing the build-up of fluid in the retina and macula.
While it sounds painful, your eyes are fully numbed before receiving an injection. The overall procedure is relatively painless and will need to be repeated over the course of months or years, varying from person to person.
Brand names of Anti-VEGF injections include Lucentis, Avastin, Beovu and Eylea.
There are a variety of steroids that can be injected or implanted directly in the eye to release a sustained dose that reduces swelling.
Some steroids can increase your risk of both cataracts and glaucoma, which means your eyecare team will need to watch your eyes closely for signs of increased pressure in your eyes.
Focal or grid laser surgery uses a small laser to treat the ruptured, leaking blood vessels. This can slow down the fluid leakage and reduce the overall swelling of the retina and macula.
Often done in conjunction with Anti-VEGF injections, your eyecare team might schedule laser surgery a few weeks or months later.